Protein Labeling Kits

Biotin‐NHS ester reagent enables simple and efficient biotin labeling of amine-containing organic molecules, antibodies, proteins and any other primary amine-containing biomolecules in solution. NH2-activated biotins require an organic solvent such as DMSO or DMF to be dissolved.

Biotin‐PEG4‐NHS Ester is a pegylated, highly hydrophilic biotinylation reagent for simple and efficient biotin labeling of antibodies, proteins and other primary amine-containing biomolecules.

Biotin‐PEG4‐NHS Ester reacts specifically and efficiently with primary amines (e.g., side chain of lysine residues or aminosilane-coated surfaces) at pH 7-9 to form covalent bonds. The hydrophilic polyethylene glycol (PEG) spacer arm of this reagent imparts water solubility that is transferred to the labeled molecule, thus reducing aggregation of labeled proteins stored in solution. The PEG spacer arm also gives the reagent a long and flexible connection to minimize steric hindrance involved with binding to avidin molecules.

Cy3‐NHS Ester is an amine-reactive Cy3 labeling dye that carries only one reactive group on each dye molecule for accurate labeling of amine groups on antibodies or oligonucleotides.

Cy3 is a bright, photostable, and pH insensitive fluorescent dye used to label antibody, proteins, peptides. Cy3 conjugates give less background than TAMRA and most other fluorophores.

Cy3 dyes are water-soluble labeling reagent. Cy3 conjugates can be excited maximally at 550 nm, with peak emission at 570 nm. For fluorescence microscopy, Cy3 can be visualized with traditional TAMRA (tetramethylrhodamine) filter sets since the excitation and emission spectra are nearly identical to those of TAMRA.

Cy5‐NHS Ester is an amine-reactive Cy5 labeling dye that carries only one reactive group on each dye molecule for accurate labeling of amine groups on antibodies or oligonucleotides.

Cy5 dyes are one of most widely used NIR fluorescent dyes. Cy5 conjugates are very bright, photostable, pH insensitive and produce minimal autofluorescence of biological specimens in this region of the spectrum.

Fluorescence of this long-wavelength Cy5 dye is not visible to the human eye but is readily detected by most imaging systems.

Cy5 dyes are water-soluble labeling reagent. Cy5 conjugates are excited maximally at 648 nm and fluoresce maximally at 665 nm. They are excited to about 98% of maximum with a krypton/argon laser (647 nm line) or to about 63% of maximum with a helium/neon laser (633 nm line).